Non‐Covalent Interactions in Polysaccharide Systems

Abstract

[Chemical structure: see text] This paper describes the behavior of some polysaccharides with well-known chemical structures and in which the influence of cooperative secondary interactions play an important role. The roles played by hydrophobic and ionic interactions (including ionic selectivity) on polysaccharide conformation and gelation are discussed. Electrostatic attractions are also important in the complexes formed between surfactants and polyelectrolytes of opposite charge. Finally, van der Waals dipolar interactions and particularly hydrogen-bond formation are examined. The role of hydrogen bonds in solubility, conformation, and especially the local stiffness of polysaccharides, but also in polymer-polymer complexes frequently obtained with polysaccharides, is developed. Repeat unit for a number polysaccharides.

Supramolecular assembled nanogel made of mannan

“…Amphiphilic polymers, over critical micellar concentration (cmc) or critical aggregation concentration (cac), are capable of selfassembling in water mainly through intra-and/or inter-molecular hydrophobic interactions [1,2]. The resulting nanometer-sized polymeric hydrogels, i.e.…”

Gelation of charged bio-nanocompartments induced by associative and non-associative polysaccharides

“…Therefore, although the polymer itself forms a network, the presence of a macroion, like a vesicle, of the same charge of the polymer opposes to the network formation. Our electrostatic-based explanation may be connected to the effect of adding iodide to polyelectrolytes [14]. The addition of salt plays an effective screening on the electrostatic repulsion and the viscosity is tremendously increased.…”

“…These charged systems are considerably sensitive to salt, so that stability and collapsing of the network can be induced by electrolyte. Several reasons are behind such phenomenon: salting-out, reduction of electrostatic repulsion [13], and the different ability of salts to form ion binding to polyelectrolytes [14].…”

Self-Assembled Hydrogel Nanoparticles for Drug Delivery Applications

“…Individually, such interactions are weak, but dominate the structural and conformational behavior of the assembly due to the large number of interactions involved [26]. While oppositely charged polysaccharides associate readily as a result of electrostatic attractions [27], interactions among neutral polysaccharides tend to be weaker, or nonexistent, a modification with chemical entities able to trigger assembly being necessary. A convenient strategy consists on linking hydrophobic grafts to e.g., a highly water-soluble polysaccharide, inducing the formation of nanoparticles via hydrophobic interactions.…”